1. Field of the Invention
The field of the present invention relates to flexible endoscopic tools that may be used in a number of endolumenal procedures. More particularly, the field of the invention pertains to flexible endoscopic tools that have roll capabilities for use during endolumenal procedures.
2. Description of the Background Art
The spread of robotic surgery has precipitated the development of novel technologies. For example, in order to enable robotically-driven endoscopes, robotically-driven tools are more useful when they are able to both articulate in a desired linear direction and roll in a desired angular direction. In current elongated medical devices, roll in the device shafts is often achieved at the expense of pull-cable management. For example, in some laparoscopic devices on the market, roll of the rigid shaft may be accomplished by simply twisting the actuation pull wires (used for manipulation of the device's end effectors and/or wrist) around each other at the same rate as the shaft. Due to mechanically-limited revolutions in either direction, the twist in the cables show little to no adverse effect on either roll or grasper manipulation. Nevertheless, this lack of pull-wire management results in noticeably varying levels of friction throughout the shaft rotations. The accumulated friction steadily increases with each rotation until the pull wires are tightly bound around one another.
FIG. 1 illustrates the physical limitations of current elongated devices arising from the implementation of roll capabilities. Specifically, FIG. 1 illustrates how the implementation of roll capabilities in a prior art device creates undesirable friction and winding of the articulation pull wires. As shown in FIG. 1, the pull wires 104 in prior art device 100 extend from the distal tip 102 and at the proximal end 101 of the device 100. Rotation of the shaft 103 forces the pull wires 104 to twist amongst one another along the entire length of the hollow shaft 103. As the shaft 103 rotates beyond a full rotation, the tensioned wires start to tightly wrap around one another much like a wire-rope. Eventually, the pull-wires 104 would not be able to overcome the resulting friction to exert tension on the elements on the distal end 102.
In competing products, such as the TransEnterix SurgiBot, articulation and roll are de-coupled using a robotic outer “sheath” to enable pitch and yaw articulation, while a flexible laparoscopic tool controls insertion roll and end-effector actuation. However, this results in an unnecessarily large system with two separate modules controlling different degrees of freedom. Separate modules complicate the pre-operative workflow because the operator must now register two sets of devices relative to the patient.
In manual endoscopes, knobs and dials actuate the distal tip of the scope while rotation of the shaft is achieved by twisting the entire proximal end of the tool. As a result, when rolling the scope, the operator is forced to contort into an uncomfortable, compensatory position in order to operate the knobs and dials. These contortions are undesirable; thus, necessitating a different approach.
Accordingly, there is a need for an endoscopic tool that is capable of rolling without compromise to its actuation and articulation capabilities, while also being ergonomically ease to use.